package com.itheima.reggie.controller;

import com.itheima.reggie.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.UUID;

@RestController
@RequestMapping("/common")
@Slf4j
public class CommonController {

    @Value("${reggie.path}")
    private String basePath;


    /**
     * @description:文件上传
     * @author: yanhongwei
     * @date: 2023/5/22 15:13
     * @param: [file]
     * @return: com.itheima.reggie.common.R<java.lang.String>
     **/
    @PostMapping("/upload")
    public R<String> upload(MultipartFile file){
        //file是一个临时文件,需要缓存到指定位置,否则本次请求完成后临时文件会删除
        log.info(file.toString());

        //原始文件名
        String originalFilename=file.getOriginalFilename();
        String suffix=originalFilename.substring(originalFilename.lastIndexOf("."));

        //使用UUID重新生存文件名,防止文件名称重复造成文件覆盖
        String fileName= UUID.randomUUID().toString()+suffix;

        //创建一个目录对象
        File dir=new File(basePath);
        //判断当前目录是否存在
        if(!dir.exists()){
            //目录不存在，需要创建
            dir.mkdirs();
        }

        try {
            file.transferTo(new File(basePath + fileName));
        } catch (IOException e) {
            e.printStackTrace();
        }

        return R.success(fileName);
    }

    /**
     * @description:文件下载
     * @author: yanhongwei
     * @date: 2023/5/23 8:55
     * @param: [name, response]
     * @return: void
     **/
    @GetMapping("/download")
    public void download(String name, HttpServletResponse response){

        try {
            //输入流，通过输入流读取文件内容
            FileInputStream fileInputStream=new FileInputStream(new File((basePath+name)));

            //输出流，通过输出流将文件写会浏览器，在浏览器展示图片了
            ServletOutputStream outputStream=response.getOutputStream();

            response.setContentType("image/jpeg");

            int len=0;
            byte[] bytes=new byte[1024];
            while((len=fileInputStream.read(bytes))!=-1){
                outputStream.write(bytes,0,len);
                outputStream.flush();
            }

            //关闭资源
            outputStream.close();
            fileInputStream.close();
        } catch (Exception e) {
            e.printStackTrace();
        }

    }

}
